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Effects of Climate Warming on Vegetative Phenology of the Common Beech Fagus sylvatica in a Submontane Forest of the Western Carpathians : Two-Decade Analysis

Schieber B., Kubov M., Janík R.

Polish Journal of Ecology

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2017

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Vol. 65, nr 3

339--351

EN

The paper examines the results of phenological research on common beech (Fagus sylvatica L.) during a period of 21 years (1995-2015) in the submontane beech forest of central Slovakia (Inner Western Carpathians). We focused on bud-burst, leaf unfolding and leaf colouring. Temporal analysis indicated that the mean monthly air temperature increased, especially from April to August. An extraordinary increase of air temperature in March and April, mostly in the last decade, was detected. The precipitation from May to August varied considerably, but in the range of the long-term mean value. During the study period, the mean/earliest/latest onset of the bud-burst of common beech was observed on the 110th/101st/120th day of the year (DOY), respectively. As for leaf unfolding 10% and 50% (LU 10 and LU 50), we found the mean/earliest/latest onset on the 114th/103rd/122nd DOY and on the 118th/108th/124th DOY, respectively. The mean/earliest/latest onset of leaf colouring 10% (LC 10) and 50% (LC 50) started on the 272nd/262nd/288th DOY and on 286th/276th/298th, respectively. A medium degree of negative correlation (r = -0.68, P < 0.05) was found between air temperature and spring plant development (LU 50). In contrast, for both the cumulative temperature and precipitation, we found very low correlation with autumnal leaf phenology (r ≤ 0.3, P > 0.05). The vegetation period of the examined tree species lasted for 168 days on average (min/max were 155/183 days). Trend analysis revealed an earlier onset of spring phenophases by 7 days/2 decades. Conversely, a delay of autumnal phenophases by 9 days was recorded, so the vegetation period of beech extended by more than two weeks during the study period.

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Effect of Tree Layer and Microsite on the Variability of Natural Regeneration in Autochthonous Beech Forests

Vacek Z., Vacek S., Podrázský V., Bílek L., Štefančík I., Moser W. K., Bulušek D., Král J., Remeš J., Králíček I.

Polish Journal of Ecology

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2015

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Vol. 63, nr 2

233--246

EN

The present study describes natural regeneration on five permanent research plots (PRP) in juvenile growth and development phases (regrowth and advanced growth) in autochthonous beech forests in Broumovské stěny National Nature Reserve located in the Protected Landscape area in the northeast part of Czech Republic. The stands of herb-rich beech forests were studied in the optimum to break-up stage. Natural regeneration was not evenly spaced but rather was clustered. Mean regeneration density ranged from 1,472 to 44,888 recruits per ha. European beech (Fagus sylvatica L.) made up 78.5–98.0% of all regeneration. Sycamore maple (Acer pseudoplatanus L.) was also relatively abundant. Regeneration dominance and abundance responded to the mature stand canopy, soil skeleton, microrelief, ground vegetation cover, and surface characteristics. The results suggest a relationship between recruit height and microrelief in 4 out of 5 PRPs. We found statistically significant differences in height of natural regeneration (F(2,18843) = 191.8, P <0.001) on mounds (74.0 cm), on slopes (119.5 cm) and on pits (121.0 cm) due to high soil skeleton content on mounds with numerous rock outputs, minimum amount of fine earth and lower water retention, both necessary for recruit growth. In addition to the character of microrelief, the growth of natural regeneration was negatively influenced by mature stand density and canopy indicators.

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Morphological plasticity of leaves in natural regeneration of Fagus sylvatica L. : effects of direct and diffuse light, ontogeny and shoot type

Jarcuska B.

Polish Journal of Ecology

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2011

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Vol. 59, nr 2

339-353

EN

It is known that the role of accessible light as a growth-determining factor in beech natural regeneration rises in importance with growth of individuals. However, the accompanied changes in leaf traits underlying this shift in light demands are not well known. The aim of this study was to investigate influence of ontogenetic stage (0.5 m high 'seedlings', 2.1 m 'saplings'), shoot type (terminal, lateral long and lateral short) and diffuse and direct light on morphological traits of leaves at spring-shoot-level in naturally regenerated beech individuals - shoot mean leaf area (mLA), shoot mean leaf weight (mLW), leaf mass per area (LMA), leaf area per shoot unit length (LAL), leaf mass per shoot unit length (LWL), number of leaves per shoot unit length (NLL), and ratio of mean-leaf width to its length (LSh). Ontogenetic drift affected the values of these traits; its influence depended on shoot type and component of light. The light explained more trait variability in saplings compared to seedlings (on average 45% vs 32%). The most evident shift was in the case of direct light - while direct light explained on average 18% of traits variability in seedlings, it was about 42% in saplings. The saplings compared with seedlings showed higher values of mLA, mLW, LMA, LAL on short shoots, LWL on lateral long and short shoots, LSh on terminal and lateral long shoots, and lower NLL values on terminal and long lateral shoots. Plastic response to light was higher in saplings than in seedlings (except mLA). Generally, the observed traits showed more plastic response to diffuse than to direct light in seedlings; the response of saplings was similar in both light components. The most plastic trait was LMA, the least LSh. Individuals of saplings displayed higher plasticity in traits close correlating with annual length growth of main axis, which suggests that saplings would benefit from increased light availability more than seedlings.

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Long-term changes in stand composition of natural forest associations on the Roztocze Highlands (Eastern Poland)

Maciejewski Z., Szwagrzyk J.

Polish Journal of Ecology

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2011

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Vol. 59, nr 3

535-549

EN

The purpose of this study was to determine the trends and rates of spontaneous changes in the structure and species composition of natural forests which are composed mostly of tree species growing at the limits of their natural range of distribution. We analyzed the demographic processes in populations of woody species in the years 1968-2005. The investigations were conducted in strictly protected areas in the Roztoczański National Park (The Roztocze Highlands, Eastern Poland) on four 0.5-ha sample plots, established in the 1960s. These plots represented three forest communities: upland fir mixed forest Abietetum polonicum (Ap), Carpathian beech forest Dentario glandulosae.Fagetum (DgF), and pine-oaks mixed forest Querco roboris.Pinetum (QrP)). Measurements were conducted in 1968, 1978 (two sample plots only) and in two study periods (1993-1995 and 2003-2005). Measurements in the last two periods included canopy trees (DBH and height) forest regeneration (saplings, seedlings and germinants) as well as dead wood (snags and coarse woody debris). The results revealed significant and dynamic changes in the studied forests. The directions and rates of changes were different among forest communities. Silver fir (Abies alba Mill.) showed continuous decrease in all the forest associations. The highest rates of change were found in the DgF forest association. Data from the last measurement showed, that the rate of fir decline has slowed down, and in some cases even a slight increase of its share was recorded. However, the continuous decrease in abundance of the fir regeneration in all study plots suggests, that fir in the near future can be partly replaced by the broadleaved species. Among them, European beech (Fagus sylvatica L.) revealed the most dynamic species. It showed a systematic increase of it.s share in stand composition, according to the number of trees and basal area in all investigated plots. The largest increase of this species was recorded in the QrP forest association. Untill 1993 hornbeam (Carpinus betulus L.) developed well in the DgF association, and it also increased in abundance in the Ap association. The last measurements confirmed large increase the number of hornbeams in the DgF association, whereas it's share in stand basal area revealed a weak downward tendency in both associations. After 1993 Norway spruce (Picea abies (L.) H. Karst.) grow only in the Ap forest communities, where its development is rather weak. The share of Norway spruce in forest composition has diminished systematically since 1968. The measurements from 2003 revealed a slight increase of the basal area of spruce and substantial decrease of its regeneration. Other tree species: Scots pine (Pinus sylvestris L.) and pedunculate oak (Quercus robur L.) in the successive measurements showed a systematic decrease of their number, basal area and share in the stand composition. There was also no natural regeneration of these species. Observed changes could be mainly attributed to natural processes of forests development (including natural disturbances) in general and to specific mechanisms of competition in forests composed of tree species growing close to the limits of their natural distribution ranges. In some cases the dynamics of researched species (hornbeam, pine and oak) can be explained as the regeneration processes of ecosystems affected previously by human activities.

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Analiza cech aerodynamicznych nasion jodły pospolitej i buka zwyczajnego

Tylek P.

Inżynieria Rolnicza

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2011

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R. 15, nr 6

247-253

PL

Zespół cech aerodynamicznych obejmuje prędkość krytyczną, współczynnik oporu oraz współczynnik lotności. Celem badań było opracowanie charakterystyk aerodynamicznych nasion jodły pospolitej i buka zwyczajnego obejmujących powyższe parametry. Uwzględniono podział nasion na dwie klasy żywotności w zależności od stopnia rozwoju zarodków, określonego metodą RTG bez kontrastu.

EN

A set of aerodynamic properties includes critical speed, coefficient of resistance, as well as coefficient of volatility. The purpose of the research was to evaluate aerodynamic characteristics of common fir seeds and common beech including the parameters above-mentioned. Division of seeds into two classes of vitality were considered in relation to the level of germs development, selected method of X-ray without a contrast agent.